The white fin tips might be new fin growth. I see something similar on my red CT's. Freaks me out sometimes.

Clamped fins are usually one of the first signs that something is wrong, however that does not always mean the betta is sick. I got one guy that has been badly clamped all summer and I have medicated him for everything you can think of and no one seems to be able to tell my what his problem is - Not even Sakura Anyways...

What worries me is not the clamped fins but that he is not eating. Are you sure the ick is gone completly?

If it was me, I would:
1) ditch the filter. Since you need to do at least 2 water changes a week anyways, the filter is just taking up valuable space. SOme people say tanks under 5 gallons can be cycled but, eh - to me, it's not worth the hassle. Plus most hve to strong of a current anyways.
2) Do a 100% water change and clean out the gravel to remove debris. From what I understand, you have already done this, yes?
3) add in a hiding place and plant that reaches the surface, even if its one of those cheap plastic tetra water wonder plants. If you remove the part that goes into the gravel, it will float at the surface. I suggest this because my guys LOVE to sleep in some kind of floating plant at night- weather it's a real plant or a fake floating plant.

For water changes, In MY opinion - I think every day is too much (unless he is being medicated). OFL suggests 2X a week even for 1 gallons. One 100% with gravel cleaning and one 50%. Maybe add in an extra 50% change if you want.

You are using water conditioner, right?

And yes - epsom can be used as a ferterlizer. I seen it on the directions and was like WTH?

Hey how is your betta doing? I think if he is sick and especially if he has external parasites more water changes would help.
And sorry to say ,you wrote that you moved the anubias to your other betta tank it really can be big problem. If he indeed has ext parasites or some kind of bacterial infection it contagious and your other fish can get sick. And if if really ext parasites then he is probably getting it too.
So be careful, every time you buy a new betta or live plant always quarantine it and never share any equipment between them.
Also if it really external parasites a lot of the the time we can diagnose it. Like Sena ask you if fish darting, trying to scratch his body on objects, or flashing, white spots on the body and if it spreaded....If diagnosed in early stages possible to treat. You was using medications don't stop it, and finish them. You can continue with aquarium salt. 2-3 tsp/gall pre pre mixed daily 100% water changes for 10 days. Always acclimate you betta when you doing 100% water changes. With ext parasites it better to keep temp about 84* that will speed up parasites life cycle and help them to fall faster, and some said even can die. If you ever will raise the temperature you need to do it gradually though .
Also if you have stress coat API it helps. If you put extra stress coat in the water fish will excess extra slime coat which will protect him from parasites.

He is moving around more, but still does not seem to be eating. I have been doing 100% water changes with 1.5 tsp of aquarium salt and I have removed the filter, leaving only the heater and the blue fake plant. I'll try to see if I can find a decent small cave like decoration for him to hide in. He looks fine externally: https://dl.dropbox.com/u/12783812/20...2000.21.09.jpg

Are the dark scales just coloring?

I hope he starts eating soon, it's been at least a week and a half he's gone without food.

Dark scales did he had them dark like that before or it something new? It seems when i look at the picture that his scales raised. Or it me? I think it can be normal coloration but if his scales slightly raised it external parasites. Increase aq salt to 2 tsp per gall. I would even suggest 3tsp/gall. Did you finish medications? Try to soak food in the garlic juice, may be it will help to stimulate his appetite. You can just soak pellet in the crashed frash garlic. Or try frozen blood worms.
EDIT:
I just magnified the picture and scales are raised, so i think it is parasites. Increase salt dosage and really watch your other betta. You moved plant from one tank to you betta. If i am right and it ext parasites your other fish will get them.
Rinse with hot water and dry out all equipment between uses - it will help to kill any parasites.

For water changes, In MY opinion - I think every day is too much (unless he is being medicated). OFL suggests 2X a week even for 1 gallons. One 100% with gravel cleaning and one 50%. Maybe add in an extra 50% change if you want.

I do a 100% water change in my 2.5 gallon just once a week. (unless a fish is sick) And it is perfectly fine. I have done that for about a year now and all my fish are always happy and healthy. :)

He looks perfectly fine to me. I don't see any raised scales and the darker scales appear to just be natural colouration.

Only thing really wrong is that the ends of his fins look like they may have a touch of fin rot. I never had much luck with keeping the fins of my CTs nice even in very soft and clean water.

Aquarium salt is not going to help with internal parasites. You need a medication with metronidazole or praziquantel to do that. If he has a poor appetite and is quite thin, it could be that he is suffering from internal parasites.

Also ich has quite a long life cycle depending on your water temperature. You can only kill it when it is in the free-swimming stage, not when it is visible as white spots on the fish. Even if ich looks like it might have cleared up, it can still be present in the aquarium and reinfect your fish.

Judging by the filter in your first picture, I would think a lot of his inactivity was caused by a too strong current. I've noticed that my bettas always become much less active whenever the baffle falls off their filter.

Yes aq salt for external parasites only. That what i though we talking about. It just when i magnified the picture look like scales are raised. And i saw similar post where betta had raised scales and you could see black coloration under scales. So i think coloration is normal unless his scales are raised. This is the link that i found and no one could figure out what it is until at the end- it was external parasites

So i think now is very important if his scales raised it ext parasites if not then just continue/finish aquarium salt with daily water changes and wash/dry out all equipment in between uses. Betta acclimating.